Email Services Overview Print

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Arrow Technology email servers are intended for reliable & secure transient email communications. We do not provide large ongoing email storage; there are many free or low cost services that provide large storage.

Typically our services are used in the following ways:

  • For individual desktop & mobile¬†email applications and the ability to share incoming emails between all email applications.
  • If full sharing of all email is required, then that is supported (see IMAP below) but only with a limited mailbox size.
  • As a smart host for organisations that have their own email services within their office. Arrow Technology provides the benefits of a secure service with anti-spam and anti-virus, which the office server can then benefit from.

IMAP versus POP

When using IMAP your email application normally sees a 'mirror' copy of all folders & emails stored on the email server, except for Sent Items which are stored in the email application. IMAP does not have an auto-delete option, so if you do not yourself delete emails, then your mailbox will fill up.

For IMAP and all folders except Sent Items, if you delete an email from the email application it then deletes the copy on the server at the same time, and any other devices using IMAP will at some point detect that same change.

POP retrieves copies of Inbox emails from the server and will then optionally automatically delete that email from the server. Your email application will let you choose if to delete emails and after how long. You can set a few days (or weeks) before deletion, which then allows other email applications to also download copies of those same incoming emails.

When using POP you would typically set your main email application to delete after a few days then all of your other email applications to never delete.

Converting IMAP to POP

You cannot change an IMAP account to POP; ultimately you have to delete the IMAP account and add a POP account, but with great care.

If you delete an IMAP account with the intention to change to POP, that can cause deletion of sent items that are stored in that email application. Also POP will subsequently only download the Inbox, hiding IMAP email that is already stored in other IMAP folders that are on the server.

Due to how IMAP works, different email applications may create folders that other email applications cannot see. Sometimes you may find you have to use webmail to do a cleanup, because webmail sees everything.

A clean transition from IMAP to POP is slightly fiddly and involves moving email from IMAP to be stored only on the computer, but it can be done.

Email Sharing

If you want to share just incoming email between various computers, the easiest method is to set them all to POP and only one of them is set to automatically delete incoming email after maybe a few days. That way all of the computers get a chance to download the incoming email before it is deleted.

If you want full email sharing between devices, you may require an email service that provides large mailboxes, or an office email server and then maybe use Arrow Technology as a Smart Host.

Using Your Own Email Server

Sometimes it looks like a good idea to connect your own email server to your office/home internet connection. If you send email directly through that internet connection, that is often a really bad idea.

Most internet service providers initially block SMTP port 25 that is required for directly sending email; you can sometimes get your internet service provider to unblock that port for you. However, what you often cannot do is get a correct reverse domain name lookup (reverse DNS) for your office/home internet address (IP address). Many email anti-spam systems use reverse DNS as one of their checks. If you do not have reverse DNS, you look like a spammer and your emails can be blocked

A correctly configured email server must have a valid reverse domain name lookup which matches the email server host name.

Not all receiving email servers will block your emails because many do not perform full anti-spam. Also, some may have whitelisted your email server to work around the incorrect configuration. However, your emails will probably be blocked to at least some recipients and your email service can be unreliable.

It is becoming increasingly common for anti-spam block/black-list services to block whole ranges of internet addresses for internet service providers. For example, large ranges of Vodafone & Spark addresses are in some third-party public block lists to stop directly sending email.

You can get around this problem by using a properly configured email service to forward your email for you. Most internet service providers do give you the ability to send email via their email servers.

  • When attaching a desktop computer to the internet, you would nearly always use a service provider to send your email for you. That might be your own internet service provider or an email service such as Google gmail, Microsoft 360 or Hotmail.
  • When your office email server sends email via another email server, that other server is often called a Smart Host.

Arrow Technology provides Smart Host services where we handle the outgoing & incoming email for office servers. Using our services allows more control over your email plus the ability to more closely monitor & analyse any issues, which can often be difficult or impossible when using some internet service providers.

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